But opposition parties pounced on the Quebec Conservative MP's comments to charge that the Harper government is finally showing its true colours as a climate change skeptic.

In a letter to La Presse newspaper, Bernier argued there is no scientific consensus on the matter and he applauded the Harper government for taking a go-slow approach.

"The debate over climate change, stifled for years by political correctness, has finally broken out in the media," he wrote in a letter published Wednesday.

"The numerous recent revelations on errors by the Intergovernmental Panel on Climate Change have supplemented the alternative theories put forward for many years.

"We can now see that it's possible to be a 'skeptic,' or in any case to keep an open mind, on just about all the main aspects of warming theory."

Canada may have taken a beating from environmentalists at last year's Copenhagen conference, but Bernier said it would have been wrong to take a deep plunge into regulating greenhouse gases.

"It would certainly be irresponsible to spend billions of dollars and impose exaggeratedly severe regulations to solve a problem whose gravity we're still far from discerning," Bernier wrote.

"The alarmism that has often characterized this issue is no longer valid. Canada is right to be prudent."

He insisted no one in the PMO saw his letter before it was sent.

A spokesman for Harper said Bernier is entitled to his own opinion but it's not shared by the government.

"Backbench MPs have the right to their view and sometimes those views are different than those of the government," said Dimitri Soudas.

"But the government's position is crystal clear. The (global warming) problem is real and we will act to solve it."

The government's most recent target is to reduce carbon emissions by 17 per cent from 2005 levels by 2020. It has yet to introduce precise measures to meet that target, arguing that Canada must harmonize its approach with that of the United States.

Bloc Quebecois Leader Gilles Duceppe asserted that Bernier was "following orders" from the PMO, hoping to get back into cabinet by echoing "exactly the same" doubts about climate change that Harper himself used to openly espouse.

In 2002, Harper referred to the Kyoto climate change accord as "a socialist scheme to suck money out of wealth-producing nations" and the science behind it as "tentative and contradictory."

In 2006, he again expressed doubts, saying, "We have difficulties in predicting the weather in one week or even tomorrow. Imagine in a few decades."

While Harper has for the last few years professed to believe in climate change, Duceppe said his lack of any real action on the issue speaks louder than words.

John Bennett of the Sierra Club agreed: "The government for the last four years has done everything it can to avoid taking action on climate change. The only explanation for that . . . is that their real views are the views expressed by Mr. Bernier."

Liberal environment critic David McGuinty said it's hard to believe Bernier was freelancing. He noted that Bernier is still touted as future cabinet material and even as a possible successor to Harper.

Harper dumped Bernier from cabinet in 2008 after the minister admitted forgetting secret documents at the home of a girlfriend with links to criminal bikers.

But all has since been forgiven. The prime minister travelled to Bernier's Beauce riding last October, where he went out of his way to praise the MP as "a great friend and a great member of my team."

McGuinty said Bernier's climate change letter "now basically raises the question about what the prime minister's position really is."

"Harper has an obligation now to stand up and explain to Canadians why he's tolerating this public view put out by a prominent member of his Quebec caucus," he said.

NDP environment critic Linda Duncan echoed that sentiment: "Is this an indication of what's discussed in the PMO and the (Tory) caucus? It raises the obvious question."